Johnson 88hp, wont run under load

surrender

Petty Officer 1st Class
Joined
Jan 25, 2009
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393
Ok guys, got boat from buddy on the cheap. Dont know any history. So far I followed info found here, changed plugs, lower unit oil, cleaned carbs, running new fuel, changed racor, ect. So today we put it in the water and it planed off once and was running and then died. Could not get it to run above high idle again. Kept wanting to die. The onlty reason we made it back was we would push the primer in when it was dying. Got it home and checked compression, 110,110,105,102. Seems ok there. Pulled pickup out of tank, looked great. Blew it out, all clear. i havent changed all the fuel lines but thats next. Checked the fuel pump filter, looks new. The fuel pump diaphram looks a little distorted but could not find a tear or hole in it. Going to get a fuel pump kit in the AM. It almost felt like we spun the prop when we first tried to run after it died the first time. It seemed to want to rev up but we would go nowhere. Then after a bit (a minute or two) it would not run above mid idle. Any pointers, if not its going to the mechanic.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Johnson 88hp, wont run under load

clogged high speed jets in carb. did you remove them, also do new fuel lines, and flush lines out be connecting to the carbs. see the TOP SECRET FILE, 1st thread in this forum. the 88 is a great power house.
 

surrender

Petty Officer 1st Class
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Jan 25, 2009
Messages
393
Re: Johnson 88hp, wont run under load

I'am going to go over the carbs again. new fuel lines-yes, but not at carbs, will do when i do fuel pump.
thanks.
 

tashasdaddy

Honorary Moderator Emeritus
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51,019
Re: Johnson 88hp, wont run under load

be sure to remove the jets. they are on the sides of the bowl.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: Johnson 88hp, wont run under load

You can verify a weak fuel pump by having someone constantly squeeze the fuel primer bulb. If the engine runs ok at high speed when the bulb is pumped-likely the fuel pump needs replacing. If this does not remedy your problem, then I'd be looking at a carb overhaul as Taz mentioned.
 
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